Re: [PATCH v4 4/5] i3c: mipi-i3c-hci: use parity8 helper instead of open coding it

[Jarkko Nikula]

On 1/7/25 11:02 AM, Wolfram Sang wrote:
> The kernel has now a generic helper for getting parity with easier to
> understand semantics. Make use of it. Here, it also fixes a bug because
> the correct algorithm is using XOR ('^=') instead of ADD ('+=').
>
> Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> Tested-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
> ---
>
> Change since v3:
>
> * updated commit message to mention the bugfix
>
> I intentionally did not add a Fixes tag because this fix depends on
> patch 1. The proper fix for backporting would change this to XOR, I'd
> think.
Stable rules allow also cherry picking additional patches. To me picking 
patch 1 and 4 sounds better than an intermediate fix since bug has been 
here from the beginning. IMHO not so urgent than a regression.

Looks like we have been lucky. First dynamic address is 0x9 and previous 
algorithm gets the same calculated dat_w0 value for at least for the 
addresses 0x9 and 0xa.